EP 1 508 399 A1 discloses a turbine blade for a gas turbine, which turbine blade, in order to prevent inadmissibly large cracks, spatially limits the growth of said cracks by a slot which runs in the region of the blade leading edge. Cracks which have developed at the blade leading edge can therefore grow in the axial direction at most only up to the slot. This leads to a prolonged service life of the turbine blade.
However, it has been found that crack development—as viewed in the direction of flow—may also occur downstream of the slot, in the center region of the blade profile. The cracks which have developed there may then spread in the direction of the trailing edge. If such a crack has a length which is greater than the maximum admissible crack length, reliable operation of a gas turbine equipped with said turbine blade is no longer ensured, so that this turbine blade has to be exchanged.